Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.

FreshBooks - The ideal accounting software for small business owners.

Recurly - Subscription billing and recurring billing management. Recurly offers enterprise-class subscription billing for thousands of companies worldwide.

Avaza - Beautiful Projects, Timesheets, Expenses, Quotes & Invoices for Small Businesses

Zuora - Zuora creates cloud-based software on a subscription basis that enables any company in any industry to successfully launch, manage, and transform into a subscription business.

Invoice2go - Full featured, invoice and estimate solution with full mobile support.